programes disapear from add remove programs

I had a bit of trouble when i tried installing a program
that i needed in that when i installed it and tried to
run it nothing happened, i wend into the folder where i
installed it to and nothing was there, after a bit of
bothering my friends i we come to the conclusion that
my "administrator" login didnt have full admin rights so
i set about correcting this by editing the registy and
setting the permissions manuly, BIG mistake, rebooted the
computer and most of the programes in "add remove
programes" had gone along with ms publisher, ms front
page, ms visio and many more, can anyone help
Please.......